在MSTest v2中的并行测试之间共享实体框架核心数据库上下文

如何解决在MSTest v2中的并行测试之间共享实体框架核心数据库上下文

我正在尝试使用this通过使用MSTest v2的多个测试共享数据库连接，不幸的是，它没有xUnit之类的Fixture。因此，我创建了一个静态类：

[TestClass]
static class DbContextFactory
{
    private static string ConnectionString = "Server=(localdb)\\MSSQLLocalDB;Initial Catalog=C4S_Test;ConnectRetryCount=0";

    /// <summary>
    /// Exposed connection for making shared transactions across multiple context instances possible
    /// </summary>
    public static DbConnection Connection;

    //called once before tests
    [AssemblyInitialize]
    public static void InitializeDbContext(TestContext context)
    {
        Connection = new SqlConnection(ConnectionString);
        Seed();
        Connection.Open();
    }

    public static C4S_DataContext CreateContext(DbTransaction transaction = null)
    {
        var context =
            new C4S_DataContext(new DbContextOptionsBuilder<C4S_DataContext>().UseSqlServer(Connection)
                .EnableSensitiveDataLogging().Options);

        if (transaction != null)
        {
            context.Database.UseTransaction(transaction);
        }

        return context;
    }

    [AssemblyCleanup]
    public static void Cleanup()
    {
        Connection.Close();
    }

    private static void Seed()
    {
        using (var context = CreateContext())
        {
            context.Database.EnsureDeleted();
            context.Database.EnsureCreated();

            //seed some data

            context.SaveChanges();
        }
    }

在测试中，我按如下方式使用C4S_DataContext：

using (var dbContext = DbContextFactory.CreateContext())
{
    //work on dbContext
}

连续运行测试可以正常运行，但是并行运行它们会在以下例外情况下结束：

    Message: 
    Test method C4S.Model.Services.Tests.PortfolioGruppenServiceTests.GetPortfolioElementeInGruppeOrderedByBezeichnungAppTest threw exception: 
    System.InvalidOperationException: Internal connection fatal error.
  Stack Trace: 
    TdsParser.TryRun(RunBehavior runBehavior,SqlCommand cmdHandler,SqlDataReader dataStream,BulkCopySimpleResultSet bulkCopyHandler,TdsParserStateObject stateObj,Boolean& dataReady)
    TdsParser.Run(RunBehavior runBehavior,TdsParserStateObject stateObj)
    TdsParser.DrainData(TdsParserStateObject stateObj)
    TdsParser.ThrowUnsupportedCollationEncountered(TdsParserStateObject stateObj)
    TdsParser.GetCodePage(SqlCollation collation,TdsParserStateObject stateObj)
    TdsParser.TryCommonProcessMetaData(TdsParserStateObject stateObj,_SqlMetaData col)
    TdsParser.TryProcessMetaData(Int32 cColumns,_SqlMetaDataSet& metaData)
    TdsParser.TryRun(RunBehavior runBehavior,Boolean& dataReady)
    SqlDataReader.TryConsumeMetaData()
    SqlDataReader.get_MetaData()
    SqlCommand.FinishExecuteReader(SqlDataReader ds,RunBehavior runBehavior,String resetOptionsString)
    SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior,Boolean returnStream,Boolean async,Int32 timeout,Task& task,Boolean asyncWrite,SqlDataReader ds)
    SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior,TaskCompletionSource`1 completion,String method)
    SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior,String method)
    SqlCommand.ExecuteReader(CommandBehavior behavior)
    SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
    DbCommand.ExecuteReader()
    RelationalCommand.Execute(IRelationalConnection connection,DbCommandMethod executeMethod,IReadOnlyDictionary`2 parameterValues)
    RelationalCommand.ExecuteReader(IRelationalConnection connection,IReadOnlyDictionary`2 parameterValues)
    SqlServerExecutionStrategy.Execute[TState,TResult](TState state,Func`3 operation,Func`3 verifySucceeded)
    Enumerable.TryGetFirst[TSource](IEnumerable`1 source,Boolean& found)
    lambda_method(Closure )
    ResultEnumerable`1.GetEnumerator()
    LinqOperatorProvider._TrackEntities[TOut,TIn](IEnumerable`1 results,QueryContext queryContext,IList`1 entityTrackingInfos,IList`1 entityAccessors)+MoveNext()
    Enumerable.TryGetFirst[TSource](IEnumerable`1 source,Boolean& found)
    Enumerable.First[TSource](IEnumerable`1 source)
    <>c__DisplayClass15_1`1.<CompileQueryCore>b__0(QueryContext qc)
    QueryCompiler.Execute[TResult](Expression query)
    EntityQueryProvider.Execute[TResult](Expression expression)
    Queryable.FirstOrDefault[TSource](IQueryable`1 source,Expression`1 predicate)

我假设存在并发问题，但无法解决。您还需要使用来自文档的开放连接来了解以下有关EF行为的信息：

连接DbConnection 现有的DbConnection用于连接数据库。如果连接处于打开状态，则EF将不会打开或关闭连接。如果连接处于关闭状态，则EF将根据需要打开和关闭连接。 Source

解决方法

不支持同时使用SqlConnection，如上所述 GitHub